This invention relates to an improved introducer tool for use with an endocardial lead having a helical fixation element.
Endocardial leads having a helical fixation element have long been accepted as a means for achieving positive fixation in atrial and ventricular pacing applications. An endocardial screw-in lead is disclosed in the co-pending application, entitled ENDOCARDIAL EXTENDABLE SCREW-IN LEAD, Ser. No. 535,318, filed Sept. 23, 1983, now U.S. Pat. No. 4,570,642. Introducer tools are used to facilitate the introduction and implantation procedure of screw-in leads, such as the introducer tool disclosed in my co-pending application, entitled INTRODUCER TOOL FOR ENDOCARDIAL SCREW-IN LEAD, filed Dec. 19, 1983, Ser. No. 562,830.
Although the introducer tool disclosed in my co-pending application Ser. No. 562,830 has been satisfactory for facilitating the introduction of the lead into a patient, there have been infrequent occasions when the stylet has buckled during the introduction procedure. The buckling of the stylet is attributable to the particular construction of the introducer tool disclosed in my earlier co-pending application Ser. No. 562,380. Although this infrequent buckling does not prevent introduction of the lead, it does interfere with smooth introduction and is annoying to the attending physician.